Deadman switch mechanism for emergency stop of robot and teaching operation

ABSTRACT

A deadman switch mechanism and a teaching operation panel equipped with the deadman switch mechanism, in which possibility of losing a safety function is low even if failure happens in a contact or other elements of a circuit. When an operator grips at least one of grip levers (GL1; GL2) with normal force, the grip levers turn around axes (AX4; AX5), shoulder portions (SD1; SD2) abut on slave levers (SL1; SL2) and turns the slave levers connected by a link (LK) around an axis (AX3) in the direction denoted by an arrow B, simultaneously, so that switches (SW1; SW2) are turned into an ON-state, simultaneously. Then, two circuits including those switches, respectively, output ON-signals independently and these signals are subjected to AND process, to allow the robot to operate. In an emergency, when an operator releases gripping of the grip levers (GL1; GL2), the slave levers (SL1; SL2) turn in the direction denoted by an arrow A, simultaneously, so that the switches (SW1; SW2) are brought into an OFF-state, simultaneously, and the robot stops immediately.

TECHNICAL FIELD

The present invention relates to a deadman switch mechanism for anemergency stop of a robot and a teaching operation panel having thedeadman switch mechanism.

BACKGROUND ART

As a switch mechanism for effecting an emergency stop of a robot, aso-called deadman switch mechanism is known. Usually, the deadman switchmechanism is provided in a teaching operation panel which is connectedto a robot controller. An operator holds the teaching operation panel,applies external operating force (pushing, holding or the like) to ahandling member (lever, button, knob, handle or the like) of the deadmanswitch, and in that state, operates a robot manually.

FIGS. 1a and 1b show an example of basic structure of a switch switchingmechanism used in a conventional deadman switch. FIG. 1a shows theswitch switching mechanism to which external operating force is notapplied, and FIG. 1b shows the switch switching mechanism to whichexternal operating force is applied. In this example, a switch SW havinga switch button SB as a movable contact element is provided in ateaching operation panel, and the switch button SB is brought into anON- or OFF-state by a lever L.

With a known mechanism, the lever L which is a handling member ispivoted to turn around an axis AX, and biased in the direction denotedby an arrow A by appropriate biasing force. The force application faceFS of the lever L to which external operating force is to be applied isexposed outside the teaching operation panel so that an operator canapply external operating force thereto (push the force application faceby a finger tip).

The switch SW is normally open. When external operating force is notapplied to the switch SW as shown in FIG. 1a, a known circuit includingthe switch SW does not send out an ON-signal. In order to operate arobot, the operator needs to push the force application face FS of thelever L to turn the lever L in the direction denoted by an arrow B tothereby push the switch button SB as shown in FIG. 1b. In that state,the circuit including the switch SW sends out an ON-signal to allow therobot to operate. Thus, the operator can operate the robot. Maintainingthe state of FIG. 1b, the operator can continue operating the robot.

When the operator wants to stop operating the robot because he feelsdanger while operating the robot or for another reason, the operatorstops pushing the lever L (the force application face FS) (for example,takes his finger tip off) to bring the switch SW back into the state ofFIG. 1a to thereby prohibit the robot from operating.

The deadman switch mechanism in which one switch and one circuit arecombined as described above has a serious problem in the way of safety.If trouble happens to a contact of such one switch or the circuitincluding such one switch, there is a risk that the robot may not beprohibited from operating though the operator stops pushing the lever L(the force application face FS), that is, the deadman switch may not doits most important function.

In order to solve the problem, (1) combining two switches and onecircuit, or (2) combining two switches and two circuits has been alreadyproposed. FIGS. 2a and 2b show an example of basic structure of a switchswitching mechanism having two switches. FIG. 2a shows the switchswitching mechanism to which external operating force is not applied,and FIG. 2b shows the switch switching mechanism to which externaloperating force is applied.

In this example, two switches SW1, SW2 having switch buttons SB1, SB2,respectively, are provided in a teaching operation panel. The switchbutton SB1 is brought into an ON- or OFF-state by a lever L1, and theswitch button SB2 is brought into an ON- or OFF-state by a lever L2.

With known mechanisms, the levers L1, L2 are separately pivoted to turnaround axes AX1, AX2, respectively, and biased in the direction denotedby an arrow A by appropriate biasing force. The force application facesFS1, FS2 of the levers L1, L2 to which external operating force is to beapplied are exposed outside the teaching operation panel so that theoperator can apply external operating force thereto (push the faces byfinger tips). The levers L1, L2 are provided to handle the switches SW1,SW2, separately. When the lever L1 is pushed, the switch SW1 comes intoan ON-state (without producing any effect on the switch SW2), and whenthe lever L2 is pushed, the switch SW2 comes into an ON-state (withoutproducing any effect on the switch SW1).

In combining such two switches SW1, SW2 with one circuit, the followingtwo modes, mode 1 and mode 2 are conceivable:

Mode 1; allowing a robot to operate on the condition that both of theswitches SW1, SW2 are on (in FIG. 2b, "and" of "and/or" is effective).

Mode 2; allowing a robot to operate on the condition that at least oneof the switches SW1, SW2 is on (in FIG. 2b, "or" of "and/or" iseffective).

In mode 1, the operator needs to continue pushing the two levers L1, L2simultaneously in order to operate the robot. This makes it very hard tohandle other handling members of the teaching operation panel (forexample, to handle a jog feeding button). Therefore, mode 2 is adopted,but if trouble happens to contacts of the switches or the circuitincluding the switches, mode 2 has the same risk as the above mentionedcase in which one switch and one circuit are combined.

Specifically, there is a risk that due to some trouble, a contact oranother part of the circuit may malfunction, so that the robot may notbe prohibited from operating though the operator stops pushing the leverL1 or L2 (the force application face FS1 or FS2), that is, the deadmanswitch may not do its most important function.

In combining two switches SW1, SW2 with two separate circuits (referredto as "circuit 1" and "circuit 2"), respectively, the following twomodes, mode 3 and mode 4 are conceivable as to how to deal with theoutputs of the circuits:

Mode 3; allowing a robot to operate on the condition that both of theswitches SW1 and SW2 are on (circuit 1 and circuit 2 are both in anON-state) (in FIG. 2b, "and" of "and/or" is effective).

Mode 4; allowing a robot to operate on the condition that at least oneof the switches SW1, SW2 is on (at least circuit 1 or circuit 2 is in anON-state)(in FIG. 2b, "or" of "and/or" is effective).

In mode 3, same as in mode 1 described above, the operator needs tocontinue pushing the two levers L1, L2 simultaneously in order tooperate the robot, so that it is very hard for the operator to handleother handling members of the teaching operation panel (for example, tohandle a jog feeding button). Therefore, mode 4 is adopted, but same asmode 2 described above, mode 4 is not free from the above mentioned riskif trouble happens to contacts of the switches or the circuits includingthe switches.

Specifically, there is a risk that due to some trouble, a contact oranother part of the circuits may malfunction, so that the robot may notbe prohibited from operating though the operator stops pushing the leverL1 or L2 (the force application face FS1 or FS2), that is, the deadmanswitch may not do its most important function.

As described above, in the conventional deadman switch mechanisms, iftrouble happens to a contact or another part of a circuit, thepossibility that the minimum safety function will not be done is large.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a deadman switch and ateaching operation panel provided with a deadman switch in which thepossibility of losing a safety function when trouble happens to acontact or another part of a circuit is much reduced, and particularlyto provide a teaching operation panel having high safety and goodoperating property.

A deadman switch mechanism for an emergency stop of a robot according tothe present invention comprises: a plurality of switches each having anON-state and an OFF-state, a switching mechanism for switching theplurality of switches between an ON-state and an OFF-state, and meansfor outputting a signal to allow a robot to operate on the conditionthat all of the plurality of switches are in an ON-state. Further,according to the present invention, the switching mechanism includes oneor more handling members having an external-operating-force receivingportion exposed outside, handling-member supporting means for supportingthose one or more handling members so that those one or more handlingmembers move in accordance with external operating force applied to theexternal-operating-force receiving portion, and switch turning meanslinked with all of those one or more handling members for simultaneouslyturning the plurality of switches to an ON-state/the OFF-state. Alinkage mechanism may be adopted as the switch turning means linked withall of the handling members.

Further, the present invention provides a teaching operation panelequipped with the deadman switch mechanism for an emergency stop of arobot, as described above. In a preferable embodiment, a plurality ofhandling members are provided, and the external-force-receiving portionsof the handling members are exposed outside a case of the teachingoperation panel at separate positions, for example, near the left andright sides of the case.

According to the present invention, since the means for simultaneouslyswitching the plurality of switches to the ON-state or the OFF-state,and the means for outputting a signal to allow a robot to operate on thecondition that all of those plurality of swishes are in the ON-state areprovided, the robot is allowed to operate only in the state where theplurality of switches are simultaneously turned into the ON-state byapplying the external operating force to any one of the one or morehandling members.

Therefore, when the whole switch mechanism operates normally, the robotis allowed to operate by applying external operating force to any one ofthe one or more handling members, and when failure happens, an emergencystop of the robot can be effected by releasing the external operatingforce (for example, taking a finger off a lever) as long as at least oneof the two switching circuit systems operates normally.

Further, operability and safety of the teaching operation panel can beespecially improved by arranging two or more handling members with theirexternal force receiving faces exposed outside at separate positionsnear the opposite sides of the teaching operation panel.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1a and 1b show an example of basic structure of a switch switchingmechanism having one switch, adopted in a conventional deadman switch,of which FIG. 1a shows the switch switching mechanism to which externaloperating force is not applied and FIG. 1b shows the switch switchingmechanism to which external operating force is applied;

FIGS. 2a and 2b show an example of basic structure of a switch switchingmechanism having two switches, adopted in a conventional deadman switch,of which FIG. 2a shows the switch switching mechanism to which externaloperating force is not applied and FIG. 2b shows the switch switchingmechanism to which external operating force is applied;

FIGS. 3a and 3b show basic structure (a first embodiment) of a switchswitching mechanism having two switches, adopted in a deadman switchaccording to the present invention, of which FIG. 3a shows the switchswitching mechanism to which external operating force is not applied andFIG. 3b shows the switch switching mechanism to which external operatingforce is applied;

FIG. 4 is a schematic view of a deadman switch mechanism in a secondembodiment of the present invention;

FIG. 5 is an outside view of a teaching operation panel adopting thedeadman switch mechanism shown in FIG. 4 for explaining how to handlethe teaching operation panel;

FIGS. 6a and 6b are views of a switch SW1 and its surrounding portion asviewed in the direction VP denoted in FIG. 4, of which FIG. 6a relatesto an OFF-state and FIG. 6b relates to an ON-state;

FIGS. 7a and 7b are schematic views as viewed in the direction VQdenoted in FIG. 4, of which FIG. 7a relates to an OFF-state and FIG. 7brelates to an ON-state;

FIGS. 8a to 8d shows examples of the outside shape of the teachingoperation panel, referred to as type 1 to type 4;

FIG. 9a is a schematic view of a third embodiment;

FIG. 9b is a schematic view of a fourth embodiment;

FIG. 10a is a schematic view of a fifth embodiment;

FIG. 10b is a schematic view of a sixth embodiment;

FIG. 11a is a schematic view of a seventh embodiment;

FIG. 11b is a schematic view of a eighth embodiment;

FIG. 12a is a schematic view of a ninth embodiment;

FIG. 12b is an illustration for explaining how to hold and handle theninth embodiment;

FIG. 13a is a schematic view of a tenth embodiment;

FIG. 13b is an illustration for explaining how to hold and handle thetenth embodiment;

FIG. 14a is a schematic view of an eleventh embodiment;

FIG. 14b is an illustration for explaining how to hold and handle theeleventh embodiment;

FIG. 15a is a schematic view of a twelfth embodiment;

FIG. 15b is an illustration for explaining how to hold and handle thetwelfth embodiment;

FIG. 16a is a schematic view of a thirteenth embodiment;

FIG. 16b is an illustration for explaining how to hold and handle thethirteenth embodiment;

FIG. 17a is a block diagram showing circuit 1 including a switch SW1,circuit 2 including a switch SW2 and a circuit for dealing with signalssent out by circuits 1, 2 which are used in the deadman switch mechanismaccording to the present invention; and

FIG. 17b is a table for explaining the relation between the output ofeach circuit and the robot's being allowed to operate or prohibited fromoperating.

BEST MODE OF CARRYING OUT THE INVENTION

With reference to FIGS. 3a and 3b, an example of basic structure of aswitch switching mechanism adopted in a basic embodiment (firstembodiment) of the present invention will be described. It is to benoted that in the drawings, similar elements are denoted by the samereference signs when it is appropriate, and that reference signs fordenoting the same elements are omitted appropriately.

In the basic structure, two switches SW1, SW2 having switch buttons SB1,SB2 as movable contact elements, respectively, are provided inside ateaching operation panel case 10 (denoted by oblique lines) on the leftand the right thereof. The switch button SB1 is brought into an ON- orOFF-state by a lever L1 which is one of handling members, and the otherswitch button SB2 is brought into an ON- or OFF-state by a lever L2which is the other of the handling members.

With a known mechanism, the levers L1, L2 which are used to switch themovable contact elements are pivoted to turn around the same one axisAX, integrally connected by a link LK, and biased in the directiondenoted by an arrow A by appropriate biasing force. The forceapplication faces FS1, FS2 of the levers L1, L2 to which externaloperating force is to be applied are exposed outside the teachingoperation panel so that an operator can apply external operating forcethereto (push the force application faces by finger tips).

The levers L1, L2 are provided to handle the switches SW1, SW2,respectively, and are in the state shown in FIG. 3a when no externaloperating force is applied to them (their force application faces FS1,FS2 (the same applies hereinafter)). Unlike the conventional structureshown in FIG. 2, since the levers L1, L2 are connected by the link LK,when the operator applies external operating force to the lever L1, thelevers L1, L2 turn in the direction denoted by an arrow Bsimultaneously, so that the switches SW1, SW2 come into an ON-state asshown in FIG. 3b, simultaneously.

Similarly, when the operator applies external operating force to thelever L2, also the lever L1 turns simultaneously with the lever L2, sothat the switches SW1, SW2 come into an ON-state simultaneously, asshown in FIG. 3b. Needless to say, also when the operator appliesexternal operating force to the levers L1, L2 simultaneously, theswitches SW1, SW2 come into an ON-state simultaneously.

Conversely, when external operating force is applied to the lever L1 orL2, the levers L1, L2 are in the state shown in FIG. 3b, and when theoperator stops applying external operating force to the lever L1 or L2,the levers L1, L2 turn in the direction denoted by an arrow Asimultaneously, so that the switches SW1, SW2 come back into anOFF-state as shown in FIG. 3a, simultaneously.

The switches SW1, SW2 are included in separate circuits 1, 2,respectively. As shown in FIG. 17a, circuits 1, 2 send out an ON- orOFF-signal, the signals sent out by circuits 1, 2 are subjected to ANDprocess, and based on the result of the AND process, the robot isallowed to operate or prohibited from operating. Specifically, as shownin FIG. 17b, the robot is allowed to operate only when the switches SW1,SW2 are both in an ON-state. Otherwise, the robot is prohibited fromoperating.

It is to be noted that since the handling members L1, L2, and thereforethe switches SW1, SW2 operate in a linked manner, only state 1 or state2 is produced as long as the whole switch mechanism including circuits1, 2 operates normally. State 3 or state 4 cannot be produced. However,also in the mechanism of the present invention, state 3 or state 4 maybe produced if abnormality happens to the circuits including the switchcontacts. In that case, however, since the robot is prohibited fromoperating, safety function is maintained. If abnormality happens to bothcircuits 1, 2 simultaneously, the robot may be allowed to operate, butthe probability thereof is considered extremely low.

In order to operate the robot, the operator pushes at least one of theforce application faces FS1, FS2 of the levers L1, L2 connected by thelink LK to turn the levers L1, L2 in the direction denoted by an arrow Bsimultaneously to thereby push the switch buttons SB1, SB2simultaneously as shown in FIG. 3b.

In that state, circuit 1 including the switch SW1 and circuit 2including the switch SW2 each send out an ON-signal. Those ON-signalsare subjected to AND process, and based on the result of the ANDprocess, the robot is allowed to operate. Thus, the operator can operatethe robot. Maintaining the state of FIG. 3b, the operator can continueoperating the robot.

When the operator wants to stop operating the robot because he feelsdanger while operating the robot or for another reason, the operatoronly needs to stop pushing the levers L1, L2 (the force applicationfaces FS1, FS2) connected by the link LK (for example, take his fingertips off). Then the levers L1, L2 come back into the state of FIG. 3a,so that the robot is prohibited from operating and stops immediately.

In the basic structure shown in FIGS. 3a and 3b, the levers L1, L2 whichare handling members directly operate on the switches. Generally, it ispossible to provide operating members which operate on the switches,apart from handling members and to link the handling members and theoperating members by an appropriate link mechanism. FIGS. 4 to 7 areillustrations for explaining such embodiment (second embodiment), ofwhich FIG. 4 is a schematic view of a mechanism, FIG. 5 is an outsideview of a teaching operation panel adopting the second embodiment forexplaining how to handle the teaching operation panel, FIG. 6 are viewsof a switch SW1 and its surrounding portion as viewed in the directionVP denoted in FIG. 4, and FIG. 7 are schematic views as viewed in thedirection VQ denoted in FIG. 4. FIG. 6a and FIG. 7a relate to anOFF-state, and FIG. 6b and FIG. 7b relate to an ON-state.

In the present embodiment of which the whole structure is mainly shownin FIGS. 4 and 7, two switches SW1, SW2 having switch buttons SB1, SB2as movable contact elements, respectively, are provided inside ateaching operation panel case 10 at its front portion (on the sideremote from an operator who is handling the teaching operation panel) onthe left and the right thereof. The switch button SB1 is brought into anON- or OFF-state by a slave lever SL1, and the other switch button SB2is brought into an ON- or OFF-state by the other slave lever SL2.

With a known mechanism, the slave levers SL1, SL2 which switch themovable contact elements SB1, SB2 are pivoted to turn around the sameone axis AX3, integrally connected by a link LK, and biased in thedirection denoted by an arrow A by appropriate biasing force.

In the present embodiment, an operator does not apply external operatingforce directly to the slave levers SL1, SL2. Instead, torque is appliedto the slave levers SL1, SL2 in the direction denoted by an arrow Bthrough grip levers GL1, GL2 which are provided as handling members.With known mechanisms, the grip levers GL1, GL2 are pivoted to turnaround axes AX4, AX5 which are parallel to each other, respectively.

The grip levers GL1, GL2 have shoulder portions SD1, SD2, respectively,and through the shoulder portions SD1, SD2, the grip levers GL1, GL2drive the slave levers SL1, SL2.

In order to handle a teaching operation panel 1 provided with thepresent mechanism, the operator holds the case 10 of the teachingoperation panel 1 provided with a display DP, for example, as shown inFIG. 5. When external operating force is not applied to the grip leverGL1 or GL2, the grip levers GL1, GL2 are in a state shown in FIG. 7a.When the operator applies normal external operating force to the griplever GL1 (grips the grip lever GL1 with normal force), for example, byhis left hand HL, the grip lever GL1 turns around the axis AX4, and theshoulder portion SD1 of the grip lever GL1 drives the slave lever SL1 toturn around the axis AX3 in the direction denoted by an arrow B.

As a result, the switch button SB1 which a movable contact element ofthe switch SW1 is pushed and the switch SW1 is brought into an ON-state,as shown on an extended scale in FIGS. 6a and 6b. The slave lever L2connected with the slave lever SL1 by the link LK also turns similarlyalong with the slave lever SL1, so that the switch SW2 is brought intoan ON-state.

Also when the operator applies normal external operating force to thegrip lever GL2 by his right hand HR (grips the grip lever GL2 withnormal force), the switches SW1, SW2 are brought into an ON-statesimultaneously, with the same mechanism.

Conversely, when external operating force is applied to the grip leverGL1 or GL2, the grip levers GL1, GL2 are in a state shown in FIGS. 6band 7b, and when the operator stops applying external operating force,the slave levers SL1, SL2 turn in the direction denoted by an arrow Asimultaneously, so that the switches SW1, SW2 come back into anOFF-state as shown in FIGS. 6a and 7a, simultaneously.

Same as in the first embodiment, the switches SW1, SW2 are included inseparate circuits 1, 2, respectively. As shown in FIG. 17a, circuits 1,2 send out an ON- or OFF-signal, the signals sent out by circuits 1, 2are subjected to AND process, and based on the result of the ANDprocess, the robot is allowed to operate or prohibited from operating.Specifically, as already explained with reference to FIG. 17b, the robotis allowed to operate only when the switches SW1, SW2 are both in anON-state. Otherwise, the robot is prohibited from operating.

Also in the present embodiment, since the slave levers SL1, SL2 whichoperate on the switches operate in a linked manner, and therefore theswitches SW1, SW2 operate in a linked manner, only state 1 or state 2 isproduced as long as the whole switch mechanism including circuits 1, 2operates normally. State 3 or state 4 cannot be produced.

State 3 or state 4 may be produced if abnormality happens to thecircuits including the switch contacts. In that case, however, since therobot is prohibited from being operated, safety function is maintained.If abnormality happens to both circuits 1, 2 simultaneously, the robotmay be allowed to operate, but the probability thereof is consideredextremely low.

In order to operate the robot, the operator holds the teaching operationpanel case 10 as shown in FIG. 5, and applies gripping force at leastone of the grip levers GL1, GL2 to turn the slave levers SL1, SL2 in thedirection denoted by an arrow B simultaneously to thereby push theswitch buttons SB1, SB2 simultaneously as shown in FIGS. 6b and 7b.

In that state, circuit 1 including the switch SW1 and circuit 2including the switch SW2 each send out an ON-signal. Those ON-signalsare subjected to AND process, and based on the result of the ANDprocess, the robot is allowed to operate. Thus, the operator can operatethe robot. Maintaining the state shown in FIGS. 6b and 7b, the operatorcan continue operating the robot.

When the operator wants to stop operating the robot because he feelsdanger while operating the robot or for another reason, the operatoronly needs to stop applying gripping force to the grip lever GL1 or GL2.Then the slave levers SL1, SL2 turn in the direction denoted by an arrowA simultaneously, and the switches SW1, SW2 comes back into an OFF-stateas shown in FIGS. 6a and 7a, so that the robot is prohibited fromoperating and stops immediately.

In the two embodiments described above, two sets of a switch, anoperating member, a handling member and the like are arranged on theleft and the right of the teaching operation panel, but other variousarrangements can be also adopted. Further, the overall shape of theteaching operation panel (or the case thereof) to which the presentinvention can be applied can be varied. It is desirable to plan thearrangement of mechanical parts, particularly of handling membersflexibly, according as the overall shape is varied.

Type 1 to type 4 shown in FIGS. 8a to 8d are typical examples of theoverall shape of a teaching operation panel (or a case thereof).Arrangements of a switch mechanism suitable for those types will bedescribed as third to thirteenth embodiments with reference to FIGS. 9to 16, in order. Description will be made simply in an itemizing manner.In FIG. 8, reference sign DP denotes a display, KY a keyboard (includingvarious handling buttons), and BH1 and BH2 holding handles.

[FIG. 9a; Applied to Type 1/Third Embodiment]

Two grip levers GL1, GL2 are arranged at the rear portion of the case(on the side closer to the operator) at both side-portions thereof toturn one slave lever SL. Two heads HD1, HD2 of the slave lever SL bringtwo switches SW1, SW2 into an ON- or OFF-state simultaneously.

[FIG. 9b; Applied to Type 1/Fourth Embodiment]

One grip lever GL is arranged at the rear portion of the case (on theside closer to the operator) at a side-portion thereof to turn one slavelever SL. Two heads HD1, HD2 of the slave lever SL bring two switchesSW1, SW2 into an ON- or OFF-state simultaneously.

[FIG. 10a; Applied to Type 1/Fifth Embodiment]

Two grip levers GL1, GL2 are arranged at the central portion of the caseat both side-portions thereof to turn one slave lever SL. Two heads HD1,HD2 of the slave lever SL bring two switches SW1, SW2 into an ON- orOFF-state simultaneously.

[FIG. 10b; Applied to Type 1/Sixth Embodiment]

One grip lever GL is arranged at the central portion of the case at aside-portion thereof to turn one slave lever SL. Two heads HD1, HD2 ofthe slave lever SL bring two switches SW1, SW2 into an ON- or OFF-statesimultaneously.

[FIG. 11a; Applied to Type 1/Seventh Embodiment]

Two handling buttons PB1, PB2 are arranged at both front corner portionsof the case to turn one slave lever SL. Two heads HD1, HD2 of the slavelever SL bring two switches SW1, SW2 into an ON- or OFF-statesimultaneously.

[FIG. 11b; Applied to Type 1/Eighth Embodiment]

One handling button PB is arranged at a front corner portion of the caseto slide one sliding slave member PS. Two heads HD1, HD2 of the slidingslave member PS bring two switches SW1, SW2 into an ON- or OFF-statesimultaneously.

[FIGS. 12a and 12b; Applied to Type 4/Ninth Embodiment]

As shown in (a), grip levers GL1, GL2 are arranged at inside portions ofholding handles BH1, BH2, respectively, to turn one slave lever SL. Twoheads HD1, HD2 of the slave lever SL bring two switches SW1, SW2 into anON- or OFF-state simultaneously. The operator handles one (or both) ofthe grip levers GL1, GL2 by his left or/and right hands as shown in (b).

[FIGS. 13a and 13b; Applied to Type 2/Tenth Embodiment]

As shown in (a), openings OP1, OP2 are formed in both side-portions ofthe case, and grip levers GL1, GL2 are arranged beside the openings,respectively, to turn one slave lever SL. Two heads HD1, HD2 of theslave lever SL bring two switches SW1, SW2 into an ON- or OFF-statesimultaneously. The operator handles one (or both) of the grip leversGL1, GL2 by his left or/and right hands using the openings OP1, OP2 asshown in (b).

[FIGS. 14a and 14b; Applied to Type 3/Eleventh Embodiment]

As shown in FIG. 14a, one grip lever GL is arranged at the front end ofthe case to turn one slave lever SL. Two heads HD1, HD2 of the slavelever SL bring two switches SW1, SW2 into an ON- or OFF-statesimultaneously. The operator handles the grip lever GL, for example, byhis left hand HL as shown in FIG. 14b.

[FIGS. 15a and 15b; Applied to Type 3/Twelfth Embodiment]

This is an example in which the present invention is applied to a smallhand-size teaching operation panel. As shown in FIG. 15a, grip leversGL1, GL2 are arranged at both side-portions of the case, respectively,to turn one slave lever SL. Two heads HD1, HD2 of the slave lever SLbring two switches SW1, SW2 into an ON- or OFF-state simultaneously. Theoperator holds the case in a manner that the case is wrapped, forexample, in his left hand BL, and handles the grip lever GL1, as shownin FIG. 15b.

[FIGS. 16a and 16b; Applied to Type 3/Thirteenth Embodiment]

One grip lever GL is arranged at a front corner portion of the case toturn one slave lever SL. Two heads HD1, HD2 of the slave lever SL bringtwo switches SW1, SW2 into an ON- or OFF-state simultaneously. Theoperator handles the grip lever GL, for example, by his left hand HL andhandles another member by his free right hand HR.

The above types of teaching operation panel and arrangements suitablethereto have been described only by way of example. It goes withoutsaying that the switch mechanism for an emergency stop of a robotaccording to the present invention can be applied to a deadman switchmechanism included in another type of teaching operation panel.

All the embodiments described above are examples in which two switchesare provided, but it goes without saying that if necessary, the numberof switches and the number of circuits can be increased in order toreduce the possibility that all the switch-circuit systems break downsimultaneously.

In the present invention, when the whole switch mechanism operatesnormally, the robot is allowed to operate by applying external operatingforce to any one of one or more handling members, and when troublehappens to the switch mechanism, an emergency stop of the robot can beeffected by stopping applying external operating force (for example,taking a finger tip off a lever) as long as at least one of the twoswitch-circuit systems operates normally. Thus, the safety of thedeadman switch is improved without harming its operating property.

The operating property and safety of the teaching operation panel isespecially improved when two or more handling members are provided withtheir force application faces being exposed outside at separatepositions near the opposite sides of the teaching operation panel.

What is claimed is:
 1. A deadman switch mechanism for an emergency stopof a robot, comprising:a plurality of switches each having an ON-stateand an OFF-state; switching means for switching said plurality ofswitches between the ON-state and the OFF-state; and means foroutputting a signal for allowing a robot to operate on the conditionthat all of said plurality of switches are in the ON-state, wherein saidswitching means includes at least one handling member having anexternal-operating-force receiving portion exposed outside, ahandling-member supporting member for supporting said at least onehandling member so that said at least one handling member moves inaccordance with an external operating force applied to saidexternal-operating-force receiving portion, and a switch turning memberlinked with all of said at least one handling member, for simultaneouslyturning said plurality of switches to the ON state/the OFF-state.
 2. Adeadman switch mechanism for an emergency stop of a robot according toclaim 1, wherein a plurality of handling members are provided as said atleast one handling member.
 3. A deadman switch mechanism for anemergency stop of a robot according to claim 1, said switch turningmeans is a linkage mechanism linked with all of said at least onehandling member.
 4. A teaching operation panel having a deadman switchmechanism for an emergency stop of a robot,said deadman switch mechanismfor an emergency stop of a robot comprising: a plurality of switcheseach having an ON-state and an OFF-state; switching means for switchingsaid plurality of switches between an ON-state and an OFF-state; andmeans for outputting a signal to allow a robot to operate on thecondition that all of said plurality of switches are in the ON-state,wherein said switching means includes at least one handling memberhaving an external-operating-force receiving portion exposed outside, ahandling-member supporting member for supporting said at least onehandling member so that said at least one handling member moves inaccordance with an external operating force applied to saidexternal-operating-force receiving portion, and a switch turning memberlinked with all of said at least one handling member, for simultaneouslyturning said plurality of switches to the ON-state/the OFF-state.
 5. Adeadman switch mechanism for an emergency stop of a robot according toclaim 4, wherein a plurality of handling members are provided as said atleast one handling member.
 6. A deadman switch mechanism for anemergency stop of a robot according to claim 5, wherein theexternal-operating-force receiving portions of said plurality ofhandling members are exposed outside a case of said teaching operationpanel at separate positions.
 7. A teaching operation panel according toclaim 6, wherein said plurality of handling members comprises twohandling members arranged on the left and the right of said teachingoperation panel, respectively, and the force application portions ofsaid handling members are exposed outside the case of said teachingoperation panel on the left and the right thereof.
 8. A deadman switchmechanism for an emergency stop of a robot, comprising:a plurality ofswitches each being switched between an ON-state and an OFF-state;swiching means for simultaneously switching all of said plurality ofswitches from the ON-state to the OFF-state, or from the OFF-state tothe ON-state in response to an operating force from an operator; andmeans for outputting a signal for allowing a robot to operate on thecondition that all of said plurality of switches are in the ON-state. 9.A deadman switch mechanism according to claim 8, wherein said switchingmeans includes a plurality of turning members respectively provided forsaid plurality of switches and to operate directly on said plurality ofswitches, a link member for mechanically linking said turning members,and at least one handling member for receiving the operating force fromthe operator and transmitting said operating force to said link member.